The Great Bear, number 111, was a locomotive of the Great Western Railway. It was the first 4-6-2 (Pacific) locomotive used on a railway in Great Britain,[1] and the only one of that type ever built by the GWR.

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There are differing views as to why Churchward and the GWR should have built a pacific locomotive in 1908 when current and future locomotive practice for the railway was centred on the 4-6-0 wheel arrangement. One suggestion is that The Great Bear was built in 1908 to satisfy demands from the directors for the largest locomotive in Britain, and much was made of the locomotive by the GWR's publicity department. However, O. S. Nock was adamant that the design "was entirely due to Churchward, and not to outside influences that pressed the project upon him".[2] Nock regarded the locomotive as "primarily an exercise in boiler design", with Churchward looking forward to a time when his Star Class locomotives could no longer cope with increasing loads.[3]

The front-end layout of the class was the same as that for the Star Class except that Churchward fitted 15 in (380 mm) diameter cylinders, the maximum possible without fouling the rear bogie wheels.[4] However, the design of the boiler was entirely new, and with a barrel of 23 ft (7.010 m)[5] which was exceptionally long both by contemporary and later standards. The main reason why Churchward adopted the 4-6-2 wheel arrangement was to enable him to fit a wide firebox over the trailing wheels. With a firebox surface of 182 sq ft (16.9 m2) this was a 17.5% increase in size compared to the Star Class.[6] It was also built with a Swindon No. 1 superheater.

With the introduction of Great Western Railway Power Classification in 1920, the power classification was "Special" (denoted by a black "+" on the red route availability disc,[7]) although the tractive effort of 27,800 lbf (124,000 N) fell within the range for "D".

In service, the performance of The Great Bear proved to be disappointing and not a significant improvement on existing classes. "The excessive tube and barrel length of 23 feet made for bulk rather than efficiency".[8] Also, the axle boxes of the trailing wheels tended to become overheated due to their proximity to the firebox. Churchward attempted to improve the locomotive's performance by adding a Swindon No. 3 Superheater in 1913 and top-feed apparatus. However, the excellent performance of the Star Class and the advent of the First World War brought a stop to further experimentation without significant improvement.

In addition to the disappointing performance, the locomotive had a highly restrictive route availability which limited its usefulness. The 20 long tons (20.320938176 t) axle load restricted it to the Paddington to Bristol main line, although it was once recorded to have travelled as far west as Newton Abbot.[1] The GWR route availability colour code for The Great Bear was Red.[7]

Although not a technical success, The Great Bear was considered the company's flagship locomotive from its introduction until Churchward's retirement in 1922.[9] With the introduction of 4073 Caerphilly Castle in 1923 with a higher tractive effort, The Great Bear ceased to have any publicity value and became an embarrassment. It was due for heavy repairs in January 1924 and so was withdrawn from service by Churchward's successor Charles Collett.[10] It had then completed a mileage of 527,272. Its regular engine driver was Thomas Blackall, originally from Aston Tirrold, Oxfordshire.

"The front portion of the original frames and the number plates were used again but probably little else".[8] No. 111 emerged as a 4-6-0 in the Castle Class, given the name Viscount Churchill. Thereafter, the GWR did not use the Pacific wheel arrangement. No. 111 was withdrawn in July 1953 and scrapped later that year. One of the original nameplates is in the Science Museum.[11]

According to Cecil J. Allen, "The Great Bear was one of the very few locomotive types that Swindon has produced, and in particular among the Churchward designs, to which the word 'failure' could be applied."[12] Authorities differ as to Churchward's attitude to his locomotive. According to Le Fleming, "his dislike of 'The Bear' was well known",[13] but Nock said that he had "a deep affection for the engine", although he came to regard it as "a white elephant" rather than a "Great Bear".[14] He was disappointed to hear of The Great Bear's destruction, and, upon hearing of Nigel Gresley's plans to construct a Pacific for the Great Northern Railway, is said to have replied: "What did that young man want to build it for? We could have sold him ours!"

1.
Great Western Railway
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The Great Western Railway was a British railway company that linked London with the south-west and west of England, the Midlands, and most of Wales. It was founded in 1833, received its enabling Act of Parliament on 31 August 1835, Goods wagons were painted red but this was later changed to mid-grey. Great Western trains included long-distance express services such as the Flying Dutchman, the Cornish Riviera Express and it also operated many suburban and rural services, some operated by steam railmotors or autotrains. The company pioneered the use of larger, more economic goods wagons than were usual in Britain and it operated a network of road motor routes, was a part of the Railway Air Services, and owned ships, docks and hotels. The Great Western Railway originated from the desire of Bristol merchants to maintain their city as the port of the country. The company was founded at a meeting in Bristol in 1833 and was incorporated by Act of Parliament in 1835. Isambard Kingdom Brunel, then aged twenty-nine, was appointed engineer and this was by far Brunels largest contract to date. Firstly, he chose to use a gauge of 7 ft to allow for the possibility of large wheels outside the bodies of the rolling stock which could give smoother running at high speeds. Secondly, he selected a route, north of the Marlborough Downs and this meant the line was not direct from to London to Bristol. From Reading heading west, the line would curve in a northerly sweep back to Bath, the first 22.5 miles of line, from Paddington station in London to Maidenhead Bridge station, opened on 4 June 1838. When Maidenhead Railway Bridge was ready the line was extended to Twyford on 1 July 1839, the cutting was the scene of a railway disaster two years later when a goods train ran into a landslip, ten passengers who were travelling in open trucks were killed. This accident prompted Parliament to pass the 1844 Railway Regulation Act requiring railway companies to provide carriages for passengers. The next section, from Reading to Steventon crossed the Thames twice, a 7. 25-mile extension took the line to Faringdon Road on 20 July 1840. Meanwhile, work had started at the Bristol end of the line, on 17 December 1840, the line from London reached a temporary terminus at Wootton Bassett Road west of Swindon and 80.25 miles from Paddington. The section from Wootton Bassett Road to Chippenham was opened on 31 May 1841, as was Swindon Junction station where the Cheltenham and Great Western Union Railway to Cirencester connected. That was an independent line worked by the GWR, as was the Bristol and Exeter Railway, in 1851, the GWR purchased the Kennet and Avon Canal, which was a competing carrier between London, Reading, Bath and Bristol. The GWR was closely involved with the C&GWUR and the B&ER, the South Wales Railway had opened between Chepstow and Swansea in 1850 and became connected to the GWR by Brunels Chepstow Bridge in 1852. It was completed to Neyland in 1856, where a port was established

2.
Swindon Works
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Swindon railway works were built by the Great Western Railway in 1841 in Swindon, Wiltshire, United Kingdom. In 1835 Parliament approved the construction of a railway between London and Bristol and its Chief Engineer was Isambard Kingdom Brunel. From 1836, Brunel had been buying locomotives from various makers for the new railway, in 1837, Brunel recruited Daniel Gooch and gave him the job of rectifying the heavy repair burden of the GWRs mixed bag of purchased locomotives. With Brunels support, Gooch made his proposal to the GWR directors, construction started immediately and they became operational on 2 January 1843. There are several stories relating to how the railway came to pass through Swindon, however Swindons midway point between GWR terminals and the topography of land near the town were more likely factors. The GWR mainline was originally planned to cut through Savernake Forest near Marlborough, but the Marquess of Ailesbury, the Marquess had previously objected to part of the Kennet and Avon Canal running through his estate. The line was laid in 1840, but the location of the works was still undecided, tracks were laid at Didcot in 1839 and for some time this seemed a more likely site. Gooch noted that the nearby Wilts and Berks Canal gave Swindon a direct connection with the Somerset coalfield, drawing water for the engines from the canals was also considered, and an agreement to this effect was completed in 1843. However, the Goddard family, following the example the Marquess of Ailesbury, objected to having it near their property, so it was laid a couple of miles further north. Initially only employing 200 men, repairs began in 1843, with the first new locomotive and this was followed by six more, with the Iron Dukes, including The Lord of the Isles, considered the fastest broad-gauge engine of its day. By 1851 the works were employing over 2000 men and were producing one locomotive a week. A rolling mill for manufacturing rails was installed in 1861, attracting workers from South Wales, although some rolling stock was built at Wolverhampton, Worcester and Saltney near Chester, most of the work was concentrated at Swindon. Like most early railways, the GWR was built with gradients and the minimum of curves. However, from 1849 Gooch also built 4-4-0 saddle tanks for the routes in Devon. The Works transformed Swindon from a small 2,500 population market town into a railway town. Built to the north of the town centre, the works had need to build locally accessible housing. The completed village provided to the medical and educational facilities that had been sorely lacking, plus St Marks Church. The terraced two-storey cottages were built on two blocks of four streets, not dissimilar in appearance to passing trains

3.
Whyte notation
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The notation counts the number of leading wheels, then the number of driving wheels, and finally the number of trailing wheels, groups of numbers being separated by dashes. Other classification schemes, like UIC classification and the French, Turkish and Swiss systems for steam locomotives, in the notation a locomotive with two leading axles in front, then three driving axles and then one trailing axle is classified as 4-6-2. Articulated locomotives such as Garratts, which are two locomotives joined by a common boiler, have a + between the arrangements of each engine. Thus a double Pacific type Garratt is a 4-6-2+2-6-4, for Garratt locomotives the + sign is used even when there are no intermediate unpowered wheels, e. g. the LMS Garratt 2-6-0+0-6-2. This is because the two units are more than just power bogies. They are complete engines, carrying fuel and water tanks, the + sign represents the bridge that links the two engines. Simpler articulated types such as Mallets, have a frame under a common boiler where there are no unpowered wheels between the sets of powered wheels. Typically, the frame is free to swing, whereas the rear frame is rigid with the boiler. Thus a Union Pacific Big Boy is a 4-8-8-4, four leading wheels, one group of eight driving wheels, another group of eight driving wheels and this numbering system is shared by duplex locomotives, which have powered wheel sets sharing a rigid frame. No suffix means a tender locomotive, T indicates a tank locomotive, in European practice, this is sometimes extended to indicate the type of tank locomotive, T means side tank, PT pannier tank, ST saddle tank, WT well tank. T+T means a tank locomotive that also has a tender, in Europe, the suffix R can signify rack or reversible, the latter being Bi-cabine locomotives used in France. The suffix F indicates a fireless locomotive, other suffixes have been used, including ng for narrow-gauge and CA or ca for compressed air. In Britain, small diesel and petrol locomotives are classified in the same way as steam locomotives. This may be followed by D for diesel or P for petrol, thus 0-6-0DE denotes a six-wheel diesel locomotive with electric transmission. Where the axles are coupled by chains or shafts or are individually driven, thus 4wPE indicates a four-wheel petrol locomotive with electric transmission. For large diesel locomotives the UIC classification is used, the main limitation of Whyte Notation is that it does not cover non-standard types such as Shay locomotives, which use geared trucks rather than driving wheels. The most commonly used system in Europe outside the United Kingdom is UIC classification, based on German practice, in American practice, most wheel arrangements in common use were given names, sometimes from the name of the first such locomotive built. For example, the 2-2-0 type arrangement is named Planet, after the 1830 locomotive on which it was first used, the most common wheel arrangements are listed below

4.
Track gauge
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In rail transport, track gauge is the spacing of the rails on a railway track and is measured between the inner faces of the load-bearing rails. All vehicles on a network must have running gear that is compatible with the track gauge, as the dominant parameter determining interoperability, it is still frequently used as a descriptor of a route or network. There is a distinction between the gauge and actual gauge at some locality, due to divergence of track components from the nominal. Railway engineers use a device, like a caliper, to measure the actual gauge, the nominal track gauge is the distance between the inner faces of the rails. In current practice, it is specified at a distance below the rail head as the inner faces of the rail head are not necessarily vertical. In some cases in the earliest days of railways, the company saw itself as an infrastructure provider only. Colloquially the wagons might be referred to as four-foot gauge wagons, say and this nominal value does not equate to the flange spacing, as some freedom is allowed for. An infrastructure manager might specify new or replacement track components at a variation from the nominal gauge for pragmatic reasons. Track is defined in old Imperial units or in universally accepted metric units or SI units, Imperial units were established in United Kingdom by The Weights and Measures Act of 1824. In addition, there are constraints, such as the load-carrying capacity of axles. Narrow gauge railways usually cost less to build because they are lighter in construction, using smaller cars and locomotives, as well as smaller bridges, smaller tunnels. Narrow gauge is often used in mountainous terrain, where the savings in civil engineering work can be substantial. Broader gauge railways are generally expensive to build and require wider curves. There is no single perfect gauge, because different environments and economic considerations come into play, a narrow gauge is superior if ones main considerations are economy and tight curvature. For direct, unimpeded routes with high traffic, a broad gauge may be preferable, the Standard, Russian, and 46 gauges are designed to strike a reasonable balance between these factors. In addition to the general trade-off, another important factor is standardization, once a standard has been chosen, and equipment, infrastructure, and training calibrated to that standard, conversion becomes difficult and expensive. This also makes it easier to adopt an existing standard than to invent a new one and this is true of many technologies, including railroad gauges. The reduced cost, greater efficiency, and greater economic opportunity offered by the use of a common standard explains why a number of gauges predominate worldwide

5.
Standard gauge
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The standard gauge is a widely used railway track gauge. Approximately 55% of the lines in the world are this gauge, all high-speed rail lines, except those in Russia, Uzbekistan, and Finland, are standard gauge. The distance between the edges of the rails is defined to be 1435 mm except in the United States. It is also called the UIC gauge or UIC track gauge, as railways developed and expanded, one of the key issues was the track gauge to be used. The result was the adoption throughout a large part of the world of a gauge of 1435 mm. In North East England, some lines in colliery areas were 4 ft 8 in. All these lines had been widened to standard gauge by 1846, parts of the United States, mainly in the Northeast, adopted the same gauge, because some early trains were purchased from Britain. However, until well into the half of the 19th century, Britain. The American gauges converged as the advantages of equipment interchange became increasingly apparent, notably, all the 5 ft broad gauge track in the South was converted to standard gauge over the course of two days beginning on 31 May 1886. See Track gauge in the United States, snopes categorized this legend as false, but commented that. It is perhaps more fairly labelled as True, but for trivial, the historical tendency to place the wheels of horse-drawn vehicles approximately 5 feet apart probably derives from the width needed to fit a carthorse in between the shafts. Others were 4 ft 4 in or 4 ft 7 1⁄2 in, the English railway pioneer George Stephenson spent much of his early engineering career working for the coal mines of County Durham. He favoured 4 ft 8 in for wagonways in Northumberland and Durham, the Hetton and Springwell wagonways also used this gauge. Stephensons Stockton and Darlington railway was primarily to transport coal from mines near Shildon to the port at Stockton-on-Tees. The initial gauge of 4 ft 8 in was set to accommodate the existing gauge of hundreds of horse-drawn chaldron wagons that were already in use on the wagonways in the mines. The railway used this gauge for 15 years before a change was made to 4 ft 8 1⁄2 in gauge, George Stephenson used the 4 ft 8 1⁄2 in gauge for the Liverpool and Manchester Railway, authorised in 1826 and opened 30 September 1830. The success of this led to Stephenson and his son Robert being employed to engineer several other larger railway projects. Monkland and Kirkintilloch Railway, authorised 1824 and opened 1825, used 4 ft 6 in, Dundee and Newtyle Railway, authorised 1829 and opened 1831, used 4 ft 6 1⁄2 in

6.
Leading wheel
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The leading wheel or leading axle or pilot wheel of a steam locomotive is an unpowered wheel or axle located in front of the driving wheels. The axle or axles of the wheels are normally located on a leading truck. Leading wheels are used to help the locomotive negotiate curves and to support the front portion of the boiler, importantly, the leading bogie does not have simple rotational motion about a vertical pivot, as might first be thought. It must also be free to slip sideways to a small extent, the sliding bogie of this type was patented by William Adams in 1865. The first use of leading wheels is commonly attributed to John B, Jervis who employed them in his 1832 design for a locomotive with four leading wheels and two driving wheels. In the Whyte system of describing locomotive wheel arrangements, his locomotive would be classified as a 4-2-0, in the UIC classification system, which counts axles rather than wheels and uses letters to denote powered axles, the Jervis would be classified 2A. Locomotives without leading trucks are generally regarded as unsuitable for high speed use, the British Railway Inspectorate condemned the practice in 1895, following an accident involving two 0-4-4s at Doublebois, Cornwall, on the Great Western Railway. A single leading axle increases stability somewhat, while a leading truck is almost essential for high-speed operation. The highest number of leading wheels on a locomotive is six as seen on the 6-2-0 Crampton type. Six-wheel leading trucks were not very popular, the Cramptons were built in the 1840s, but it was not until 1939 that the PRR used one on the S1. AAR wheel arrangement Adams axle Trailing wheel UIC classification Whyte notation

7.
Driving wheel
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Driving Wheel, also called Drivin Wheel or Driving Wheel Blues, is blues song recorded by Roosevelt Sykes in 1936. It became a standard of the blues and has been recorded by artists, including Junior Parker and Al Green. Roosevelt Sykes Driving Wheel Blues is a solo twelve-bar blues, with Sykes providing piano accompaniment to his vocal, the song is performed at a medium tempo with the opening lyrics, Sykes recorded the song on February 18,1936 for Decca Records. It was released before Billboard magazine or a service began tracking such singles. He later recorded additional studio and live versions of the song, Junior Parker, as Little Junior Parker, recorded Driving Wheel for Duke Records in 1960 or 1961. Although Parkers vocal line and lyrics follow Sykes version, the uses a group arrangement with a horn section. Most subsequent versions of Driving Wheel show Parkers influence, including the bass line. When the song was released in 1961, it spent eleven weeks in the US Billboard R&B chart, in 1971, soul/gospel singer Al Green recorded the song in Memphis for Hi Records. His song peaked at number 46 in the R&B chart and reached number 115 on the Bubbling Under Hot 100 Singles pop chart, the song is included on the 1971 Al Green Gets Next to You album as well as various compilation albums. Greens version uses a different arrangement, in keeping with his soul music approach, Driving Wheel has been recorded by a variety of artists, including B. B. King, Paul Butterfield Blues Band, Junior Wells, Albert King, Luther Allison, and Etta James. It has, in addition, been performed live by Trigger Hippy, the band, Driving Wheel, featuring former Shamans Harvest members Ryan Tomlinson and Craig Wingate, was named after the song

8.
Trailing wheel
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On a steam locomotive, a trailing wheel or trailing axle is generally an unpowered wheel or axle located behind the driving wheels. The axle of the wheels is usually located in a trailing truck. On some large locomotives, an engine was mounted on the trailing truck to provide extra tractive effort when starting a heavy train. Trailing wheels were used in early locomotives but fell out of favor for a time during the latter 19th century. As demand for more powerful locomotives increased, trailing wheels began to be used to support the crew cab, trailing wheels first appeared on American locomotives between 1890 and 1895, but their axle worked in rigid pedestals. It enabled boilers to be lowered, since the top of the frames was dropped down behind the driving wheels. The firebox could also be longer and wider, increasing the surface area and steam generation capacity of the boiler. One-piece cast-steel trailer trucks were developed about 1915, to provide the strength for a booster engine to be fitted to the trailing axle. Finally, about 1921 the Delta trailing truck was developed with a centering device at the rear ends of the truck frame. Delta trucks were soon enlarged to carry four trailing wheels, in the Whyte notation, trailing wheels are designated by the last numbers in the series. For example, the 2-8-2 Mikado type locomotive had two leading wheels, eight driving wheels, and two trailing wheels, some locomotives such as the 4-4-0 American type had no trailing wheels and were designated with a zero in the final place. In the UIC classification system, the number of rather than the number of wheels is counted. AAR wheel arrangement Steam locomotive nomenclature UIC classification Whyte notation

9.
Wheelbase
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In both road and rail vehicles, the wheelbase is the distance between the centers of the front and rear wheels. For road vehicles with more than two axles, the wheelbase is defined as the distance between the axle and the centerpoint of the driving axle group. In the case of a truck, the wheelbase would be the distance between the steering axle and a point midway between the two rear axles. The wheelbase of a vehicle equals the distance between its front and rear wheels, at equilibrium, the total torque of the forces acting on a vehicle is zero. So, for example, when a truck is loaded, its center of gravity shifts rearward, the amount the vehicle sinks will depend on counter acting forces like the size of the tires, tire pressure, and the stiffness of the suspension. If the vehicle is accelerating or decelerating, extra torque is placed on the rear or front tire respectively, so, as is common experience, when the vehicle accelerates, the rear usually sinks and the front rises depending on the suspension. Likewise, when braking the front noses down and the rear rises, because of the effect the wheelbase has on the weight distribution of the vehicle, wheelbase dimensions are crucial to the balance and steering. For example, a car with a greater weight load on the rear tends to understeer due to the lack of the load on the front tires. This is why it is crucial, when towing a single-axle caravan, likewise, a car may oversteer or even spin out if there is too much force on the front tires and not enough on the rear tires. Also, when turning there is lateral torque placed upon the tires which imparts a turning force that depends upon the length of the distances from the CM. Wheelbases provide the basis for one of the most common vehicle size class systems, some luxury vehicles are offered with long-wheelbase variants to increase the spaciousness and therefore the luxury of the vehicle. Prime Minister of the United Kingdom Tony Blair was given a version of the Rover 75 for official use. In contrast, coupé varieties of vehicles such as the Honda Accord are usually built on shorter wheelbases than the sedans they are derived from. The wheelbase on many commercially available bicycles and motorcycles is so short, relative to the height of their centers of mass, in skateboarding the word wheelbase is used for the distance between the two inner pairs of mounting holes on the deck. This is different from the distance between the centers of the two wheel pairs. A reason for this use is that decks are sold with prefabricated holes. It is therefore easier to use the holes for measuring and describing this characteristic of the deck. A common misconception is that the choice of wheelbase is influenced by the height of the skateboarder, however, the length of the deck would then be a better candidate, because the wheelbase affects characteristics useful in different speeds or terrains regardless of the height of the skateboarder

10.
Tonne
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The SI symbol for the tonne is t, adopted at the same time as the unit itself in 1879. Its use is also official, for the metric ton, within the United States, having been adopted by the US National Institute of Standards and it is a symbol, not an abbreviation, and should not be followed by a period. Informal and non-approved symbols or abbreviations include T, mT, MT, in French and all English-speaking countries that are predominantly metric, tonne is the correct spelling. Before metrication in the UK the unit used for most purposes was the Imperial ton of 2,240 pounds avoirdupois, equivalent to 1,016 kg, differing by just 1. 6% from the tonne. Ton and tonne are both derived from a Germanic word in use in the North Sea area since the Middle Ages to designate a large cask. A full tun, standing about a high, could easily weigh a tonne. An English tun of wine weighs roughly a tonne,954 kg if full of water, in the United States, the unit was originally referred to using the French words millier or tonneau, but these terms are now obsolete. The Imperial and US customary units comparable to the tonne are both spelled ton in English, though they differ in mass, one tonne is equivalent to, Metric/SI,1 megagram. Equal to 1000000 grams or 1000 kilograms, megagram, Mg, is the official SI unit. Mg is distinct from mg, milligram, pounds, Exactly 1000/0. 453 592 37 lb, or approximately 2204.622622 lb. US/Short tons, Exactly 1/0. 907 184 74 short tons, or approximately 1.102311311 ST. One short ton is exactly 0.90718474 t, imperial/Long tons, Exactly 1/1. 016 046 9088 long tons, or approximately 0.9842065276 LT. One long ton is exactly 1.0160469088 t, for multiples of the tonne, it is more usual to speak of thousands or millions of tonnes. Kilotonne, megatonne, and gigatonne are more used for the energy of nuclear explosions and other events. When used in context, there is little need to distinguish between metric and other tons, and the unit is spelt either as ton or tonne with the relevant prefix attached. *The equivalent units columns use the short scale large-number naming system used in most English-language countries. †Values in the equivalent short and long tons columns are rounded to five significant figures, ǂThough non-standard, the symbol kt is also sometimes used for knot, a unit of speed for sea-going vessels, and should not be confused with kilotonne. A metric ton unit can mean 10 kilograms within metal trading and it traditionally referred to a metric ton of ore containing 1% of metal. In the case of uranium, the acronym MTU is sometimes considered to be metric ton of uranium, in the petroleum industry the tonne of oil equivalent is a unit of energy, the amount of energy released by burning one tonne of crude oil, approximately 42 GJ

11.
Bogie
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A bogie is a chassis or framework carrying wheels, attached to a vehicle, thus serving as a modular subassembly of wheels and axles. Bogies take various forms in various modes of transport, while bogie is the preferred spelling and first-listed variant in various dictionaries, bogey and bogy are also used. A bogie in the UK, or a truck, wheel truck. In Indian English, bogie may also refer to a railway carriage. In South Africa, the bogie is often alternatively used to refer to a freight or goods wagon. The first standard gauge British railway to build coaches with bogies, an alternate configuration often is used in articulated vehicles, which places the bogies under the connection between the carriages or wagons. Most bogies have two axles, but some cars designed for heavy loads have more axles per bogie, heavy-duty cars may have more than two bogies using span bolsters to equalize the load and connect the bogies to the cars. Suspension to absorb shocks between the frame and the rail vehicle body, Common types are coil springs, or rubber airbags. At least one wheelset, composed of an axle with bearings and a wheel at each end The bolster, the railway car is supported at the pivot point on the bolster. Axle box suspensions absorb shocks between the bearings and the bogie frame. The axle box suspension usually consists of a spring between the frame and axle bearings to permit up-and-down movement, and sliders to prevent lateral movement. A more modern design uses solid rubber springs, brake equipment, Two main types are used, brake shoes that are pressed against the tread of the wheel, and disc brakes and pads. More modern, bolsterless bogie designs omit these features, instead taking advantage of the movement of the suspension to permit rotational movement. The Commonwealth bogie, manufactured by the English Steel Corporation under licence from the Commonwealth Steel Company in Illinois, fitted with SKF or Timken bearings, it was introduced in the late 1950s for all BR Mark 1 vehicles. It was a heavy, cast-steel design weighing about 6.5 long tons, with sealed roller bearings on the axle ends, the leaf springs were replaced by coil springs running vertically rather than horizontally. The advanced design gave a better quality than the BR1. The side frame of the bogie was usually of bar construction, with simple horn guides attached, the axle boxes had a cast-steel equaliser beam or bar resting on them. The bar had two steel coil springs placed on it and the bogie frame rested on the springs, the effect was to allow the bar to act as a compensating lever between the two axles and to use both springs to soften shocks from either axle

12.
Coal
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Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams. The harder forms, such as coal, can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure. Coal is composed primarily of carbon, along with quantities of other elements, chiefly hydrogen, sulfur, oxygen. A fossil fuel, coal forms when plant matter is converted into peat, which in turn is converted into lignite, then sub-bituminous coal, after that bituminous coal. This involves biological and geological processes that take place over time, throughout history, coal has been used as an energy resource, primarily burned for the production of electricity and heat, and is also used for industrial purposes, such as refining metals. Coal is the largest source of energy for the generation of electricity worldwide, the extraction of coal, its use in energy production and its byproducts are all associated with environmental and health effects including climate change. Coal is extracted from the ground by coal mining, since 1983, the worlds top coal producer has been China. In 2015 China produced 3,747 million tonnes of coal –47. 7% of 7,861 million tonnes world coal production, in 2015 other large producers were United States, India, European Union and Australia. The word originally took the col in Old English, from Proto-Germanic *kula. In Old Turkic languages, kül is ash, cinders, öčür is quench, the compound charcoal in Turkic is öčür kül, literally quenched ashes, cinders, coals with elided anlaut ö- and inflection affixes -ülmüş. At various times in the geologic past, the Earth had dense forests in low-lying wetland areas, due to natural processes such as flooding, these forests were buried underneath soil. As more and more soil deposited over them, they were compressed, the temperature also rose as they sank deeper and deeper. As the process continued the plant matter was protected from biodegradation and oxidation and this trapped the carbon in immense peat bogs that were eventually covered and deeply buried by sediments. Under high pressure and high temperature, dead vegetation was slowly converted to coal, as coal contains mainly carbon, the conversion of dead vegetation into coal is called carbonization. The wide, shallow seas of the Carboniferous Period provided ideal conditions for coal formation, the exception is the coal gap in the Permian–Triassic extinction event, where coal is rare. Coal is known from Precambrian strata, which predate land plants — this coal is presumed to have originated from residues of algae, in its dehydrated form, peat is a highly effective absorbent for fuel and oil spills on land and water. It is also used as a conditioner for soil to make it able to retain. Lignite, or brown coal, is the lowest rank of coal, jet, a compact form of lignite, is sometimes polished and has been used as an ornamental stone since the Upper Palaeolithic

13.
Cylinder (locomotive)
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The cylinders of a steam locomotive are the components that convert the power stored in the steam into motion. Cylinders may be arranged in different ways. On early locomotives, such as Puffing Billy, the cylinders were often set vertical, the next stage, for example Stephensons Rocket, was to drive the wheels directly from steeply inclined cylinders placed at the back of the locomotive. Direct drive became the standard arrangement, but the cylinders were moved to the front, the front-mounted cylinders could be placed either inside or outside. The reason for this difference is unclear, from about 1920, outside cylinders became more common in the UK but many inside-cylinder engines continued to be built. Inside cylinders give a stable ride with less yaw or nosing. Some designers used inside cylinders for aesthetic reasons, the demand for more power led to the development of engines with three cylinders or four cylinders. As the cylinders are double-acting this gives four impulses per revolution, on a three-cylinder engine, two arrangements are possible, cranks set to give six equally spaced impulses per revolution – the usual arrangement. For a given tractive effort and adhesion factor, a locomotive of this design will be less prone to wheelslip when starting than a 2-cylinder locomotive. Outside cranks set at 90 degrees, inside crank set at 135 degrees and this arrangement was sometimes used on three-cylinder compound locomotives which used the outside cylinders for starting. This will give evenly spaced exhausts when the engine is working compound, two arrangements are also possible on a four-cylinder engine, all four cranks set at 90 degrees. With this arrangement the cylinders act in pairs, so there are four impulses per revolution, most four-cylinder engines are of this type. Pairs of cranks set at 90 degrees with the pair set at 45 degrees to the outside pair. This gives eight impulses per revolution and it increases weight and complexity, by requiring four sets of valve gear, but gives smoother torque and reduces the risk of slipping. This was relatively unusual in British practice but was used on the SR Lord Nelson class, such locomotives are easily distinguished by their exhaust beats, whicb occur at twice the frequency of a normal 2- or 4-cylinder engine. The valve chests or steam chests which contain the slide valves or piston valves may be located in various positions, if the cylinders are small, the valve chests may be located between the cylinders. For larger cylinders the valve chests are usually on top of the cylinders but, in early locomotives, the valve chests are usually on top of the cylinders but, in older locomotives, the valve chests were sometimes located alongside the cylinders and inserted through slots in the frames. This meant that, while the cylinders were outside, the valves were inside, there are many variations in the location of the valve gear

14.
Tractive force
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In railway engineering, the term tractive effort is often used synonymously with tractive force to describe the pulling or pushing capability of a locomotive. The published tractive force value for any vehicle may be theoretical—that is, the term tractive effort is often qualified as starting tractive effort, continuous tractive effort and maximum tractive effort. The product of μ and m is the factor of adhesion, Starting tractive effort, Starting tractive effort is the tractive force that can be generated at a standstill. This figure is important on railways because it determines the maximum weight that a locomotive can set into motion. Maximum tractive effort, Maximum tractive effort is defined as the highest tractive force that can be generated under any condition that is not injurious to the vehicle or machine. In most cases, maximum tractive effort is developed at low speed, due to the relationship between power, velocity and force, described as, P = vF or P/v = F tractive effort inversely varies with speed at any given level of available power. Continuous tractive effort is often shown in graph form at a range of speeds as part of a tractive effort curve, the period of time for which the maximum continuous tractive effort may be safely generated is usually limited by thermal considerations. Such as temperature rise in a traction motor, specifications of locomotives often include tractive effort curves, showing the relationship between tractive effort and velocity. The shape of the graph is shown at right, the line AB shows operation at the maximum tractive effort, the line BC shows continuous tractive effort that is inversely proportional to speed. Tractive effort curves often have graphs of rolling resistance superimposed on them—the intersection of the rolling resistance graph, once in motion, the train will develop additional drag as it accelerates due to aerodynamic forces, which increase with the square of the speed. Drag may also be produced at speed due to truck hunting, if acceleration continues, the train will eventually attain a speed at which the available tractive force of the locomotive will exactly offset the total drag, causing acceleration to cease. This top speed will be increased on a due to gravity assisting the motive power. Tractive effort can be calculated from a locomotives mechanical characteristics, or by actual testing with drawbar strain sensors. Power at rail is a term for the available power for traction, that is. An estimate for the effort of a single cylinder steam locomotive can be obtained from the cylinder pressure, cylinder area, stroke of the piston. The torque developed by the motion of the piston depends on the angle that the driving rod makes with the tangent of the radius on the driving wheel. For a more useful value an average value over the rotation of the wheel is used, the driving force is the torque divided by the wheel radius. Modern locomotives with roller bearings were probably underestimated, european designers used a constant of 0.6 instead of 0.85, so the two cannot be compared without a conversion factor

15.
Great Western Main Line
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The Great Western main line is a main line railway in Great Britain, that runs westwards from Londons Paddington station to Bristol Temple Meads. It was the route of the pre-1948 Great Western Railway which was merged into the Western Region of British Railways and is now a part of the national rail system managed by Network Rail. The line is currently being electrified and it was electrified from Paddington to Heathrow Airport in the late 1990s. Work to electrify the remainder of the started in 2011 with an initial aim to complete the work all the way to Bristol by 2016. The programme however has been deferred for six years with no end completion forecast because costs have tripled. The four sections that are delayed are, Oxford to Didcot Parkway, Bristol Parkway to Bristol Temple Meads, Bath Spa to Bristol Temple Meads and the Thames Valley branches to Henley and Windsor. The line was built by the Great Western Railway and engineered by Isambard Kingdom Brunel as a track line using a wider 7 ft broad gauge and was opened in stages between 1838 and 1840. The alignment was so level and straight it was nicknamed ‘Brunel’s Billiard Table’ and it was supplemented with a third rail for dual gauge operation allowing standard gauge 4 ft 8 1⁄2 in trains to also operate on the route in stages between 1854 and 1875. The broad gauge remained in use until 1892, evidence of the original broad gauge can still be seen at many places where bridges are a wider than usual, or where tracks are ten feet apart instead of the usual six. The original dual tracks were widened to four track in places between 1877 and 1899. Further widenings of the line took place between 1903 and 1910, the railways returned to direct government control during World War II before being nationalised to form British Railways in 1948. More widening infrastructure work took place between 1931 and 1932, and the extension to south wales was quadrupled 1941, the line speed was upgraded in the 1970s to support the introduction of the InterCity 125. Under the 1979–90 Conservative governments that succeeded the 1976–79 Labour government the proposal was not implemented, the route of the GWML includes dozens of listed buildings and structures, including tunnel portals, bridges and viaducts, stations, and associated hotels. Grade I listed structures on the line include London Paddington, Wharncliffe Viaduct, the 1839 Tudor gothic River Avon Bridge in Bristol, from London to Didcot, the line follows the Thames Valley, crossing the River Thames three times, including on the famous Maidenhead Railway Bridge. After Swindon, trains pass the Swindon Steam Railway Museum, from Wootton Bassett there are two different routes to Bristol, firstly via Box Tunnel and secondly via Bristol Parkway. It is also possible to run via the Wessex Main Line, beyond Bristol, some trains continue on the Bristol to Taunton Line to Weston-super-Mare or beyond. Main line and local services are provided by Great Western Railway, the stations served by trains between London Paddington and Bristol Temple Meads are, Slough, Reading, Didcot Parkway, Swindon, Chippenham, and Bath Spa. Local services on this route are operated by GWR and BAA under the Heathrow Connect name

16.
London Paddington station
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Paddington, also known as London Paddington, is a central London railway terminus and London Underground station complex, located on Praed Street in the Paddington area. The site has been the London terminus of the Great Western Railway, much of the main-line station dates from 1854 and was designed by Isambard Kingdom Brunel. It was first served by London Underground trains in 1863, as the western terminus of the Metropolitan Railway. Today, Paddington tube station is served by the Bakerloo, Circle, District and it is also the terminus for the Heathrow Express and Heathrow Connect services to and from London Heathrow Airport. It is one of 19 stations in the United Kingdom managed directly by Network Rail and it is situated in fare zone 1. The station complex is bounded at the front by Praed Street and at the rear by Bishops Bridge Road, on the west side of the station is Eastbourne Terrace, while the east side is bounded by the Paddington arm of the Grand Union Canal. The station is in a cutting, a fact obscured at the front by a hotel building. The surrounding area is residential, and includes the major St Marys Hospital, restaurants. Until recently there was little office accommodation in the area, however, recent redevelopment of derelict railway and canal land, marketed as Paddington Waterside, has resulted in new office complexes nearby. In addition to the Underground stations at Paddington, Lancaster Gate tube station on the Central line is a walk away to the south. A little further to the south lie the conjoined parks of Hyde Park, the National Rail station is officially named London Paddington, a name commonly used outside London but rarely by Londoners, who call it just Paddington, as on the London Underground map. Parts of the station, including the train shed, date from 1854. It is one of 19 stations managed by Network Rail, the first station was a temporary terminus for the GWR on the west side of Bishops Bridge Road, opened on 4 June 1838. The first GWR service from London to Taplow, near Maidenhead, after the main station opened in 1854, this became the site of the goods depot. It opened on 29 May 1854, the glazed roof is supported by wrought iron arches in three spans, respectively spanning 68 feet,102 feet and 70 feet. The roof is 699 feet long, and the original roof spans had two transepts connecting the three spans and it is commonly believed that these were provided by Brunel to accommodate traversers to carry coaches between the tracks within the station. However recent research, using documents and photographs, does not seem to support this belief. The Great Western Hotel was built on Praed Street in front of the station in 1851–1854 by architect Philip Charles Hardwick, the station was substantially enlarged in 1906–1915 and a fourth span of 109 feet was added on the north side, parallel to the others

17.
Bristol Temple Meads railway station
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Bristol Temple Meads is the oldest and largest railway station in Bristol, England. It is an important transport hub for transport in the city. In addition to the services there are bus services to many parts of the city and surrounding districts. Bristols other main station, Bristol Parkway, is on the northern outskirts of the conurbation. Temple Meads was opened on 31 August 1840 as the terminus of the Great Western Railway from London Paddington,116 miles 31 chains from Paddington. The railway was the first one designed by the British engineer Isambard Kingdom Brunel, soon the station was also used by the Bristol and Exeter Railway, the Bristol and Gloucester Railway, the Bristol Harbour Railway and the Bristol and South Wales Union Railway. To accommodate the number of trains, the station was expanded in the 1870s by Francis Fox. Brunels terminus is no part of the operational station. The historical significance of the station has been noted, and most of the site is Grade I listed, the platforms are numbered 1 to 15 but passenger trains are confined to just eight tracks. Most platforms are numbered separately at each end, with odd numbers at the east end, Platform 2 is not signalled for passenger trains, and there is no platform 14. Temple Meads is managed by Network Rail and the majority of services are operated by the present-day Great Western Railway, other operators are CrossCountry and South West Trains. In the 12 months to March 2014,9.5 million entries, the name Temple Meads derives from the nearby Temple Church, which was gutted by bombing during World War II. The word meads is a derivation of mæd, an Old English variation of mædwe, meadow, as late as 1820 the site was undeveloped pasture outside the boundaries of the old city, some distance from the commercial centre. It lay between the Floating Harbour and the cattle market, which was built in 1830. The original terminus was built in 1839–41 for the Great Western Railway, the first passenger railway in Bristol, and was designed by Isambard Kingdom Brunel and it was built to Brunels 7 ft broad gauge. The station was on a viaduct to raise it above the level of the Floating Harbour and River Avon, the latter being crossed via the grade I listed Avon Bridge. The station was covered by a 200-foot train shed, extended beyond the platforms by 155 feet into a storage area, Train services to Bath commenced on 31 August 1840 and were extended to Paddington on 30 June 1841 following the completion of Box Tunnel. A few weeks before the start of the services to Paddington the Bristol and Exeter Railway had opened, on 14 June 1841, its trains reversing in and out of the GWR station

18.
GWR 4073 Class
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The 4073 Class or Castle class were 4-6-0 steam locomotives of the Great Western Railway design built between 1923 and 1950. They were designed by the railways Chief Mechanical Engineer, Charles Collett, the Star class were designed to take the top express trains on the GWR with 61 in service by 1914, but after World War 1 there was a need for an improved design. To meet this need Chief Mechanical Engineer GJ Churchward had in mind an enlarged Star class design with a standard No.7 boiler, as fitted to his GWR4700 Class express freight 2-8-0 design. However, this combination would have taken the load of such a design over the 20 ton limit then set by the civil engineers. Colletts solution was to take the layout of the Star with an extended frame. The increased amount of steam that this produced allowing an increase in the diameter from 15 in ×26 in to 16 in ×26 in. The extended frame allowed for a side window cab and a grate area. The result was an increase in effort to 31,625 lb. Unlike the Star class, there was no prototype, thereafter the remaining eight locomotives came out at regular intervals until April 1924. They were 4073-4082, the series continuing unbroken from the Star class. The last 12 Star class locomotives, which were built in 1922-23, had given names of Abbeys in the western area served by the GWR. The new locomotives were named after castles also in the west beginning with Caerphilly Castle, over the twenty-seven years from August 1923 to August 1950155 Castles were built new at Swindon Works and a further sixteen were converted from other classes. In February 1952, two engines,4082 Windsor Castle and 7013 Bristol Castle swapped names and numbers with each other because King George VI died,7013 was disguised as 4082 to run the funeral train and the two engines never swapped back. 4082 was withdrawn from service in 1964 as 7013 and 7013 was withdrawn from service as 4082 in 1965, all the new builds were as follows. Great Western Railway Lot 224, Nos.4073 -4082 delivered August 1923 - April 1924, Lot 232, Nos.4083 -4092 delivered May to August 1925. Lot 234, Nos. 4093-4099 and 5000 to 5012 delivered May 1926 - July 1927, Lot 280, Nos. 5013-22 delivered June - August 1932. Lot 295, Nos. 5023-32 delivered June - August 1932, Lot 296, Nos. 5033-42 delivered May - July 1933. Lot 303, Nos. 5043-67 delivered March 1936 - July 1937, Lot 310, Nos. 5068-82 delivered June 1938 - June 1939

19.
GWR 4000 Class
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The Great Western Railway 4000 or Star were a class of 4-cylinder 4-6-0 Ten Wheeler passenger steam locomotives designed by George Jackson Churchward for the Great Western Railway in 1906. The prototype was built as a 4-4-2 Atlantic and they proved to be a successful design which handled the heaviest long distance express trains and established the design principles for GWR 4-cylinder classes over the next twenty-five years. After finally converting the last broad gauge lines in 1892, the GWR began a period of modernization as new cut-off lines shortened its routes to west of England, South Wales and Birmingham. He therefore persuaded the GWR to acquire three French 4-cylinder 4-4-2 compound locomotives,102 La France and 103 President and 104 Alliance for comparison purposes. In addition to acquiring the French compound locomotives Churchward built and tested his own prototype 4-cylinder locomotive simple-expansion locomotive, as with some early members of the Saint class it was built as a 4-4-2 but designed so that it could easily be converted to a 4-6-0. It was completed at the Swindon Works of the GWR in April 1906 and it was numbered 40 and later that year was named North Star. In November 1909 it was converted to 4-6-0, the new design incorporated many ideas from the French locomotives including a domeless taper boiler and Belpaire firebox. The design had divided drive with the outside cylinders connected to the set of driving wheels whilst the inside cylinders were connected to the front set of driving wheels. The valve gear was a design, called scissors gear, which eschewed the use of eccentrics. The prototype locomotive was rebuilt as a member of the Castle Class in November 1929, the production series were therefore all built with a 4-6-0 wheel arrangement. They also had inside walschaerts valve gear rather than the scissors gear. All except for No.4010 Western Star were built without superheaters, No.4010 received a Swindon No.1 superheater and the remainder received superheated boilers between August 1909 and October 1912. No.4009 Shooting Star was rebuilt as a member of the Castle Class in April 1925, the surviving members of the series were withdrawn 1932-1951, although No.4003 Lode Star was preserved. A second series of ten locomotives appeared in 1908, with improved bogies, numbered 4011–20. Nos.4011 was built with a Swindon No.1 superheater and they were withdrawn between 1932 and 1951. A third series of ten locomotives appeared during 1909, numbered 4021-30. The framing for these had curved ends under the cab and over the cylinders, in June 1909, No.4021 King Edward was built with a Swindon No.3 superheater but the remainder had saturated steam boilers until 1910-13. The class were all renamed during 1927 to allow for their names to be used on the new King Class, instead, they were given names of a country followed by the word Monarch. However, several of the names relating to enemy countries were removed during the Second World War and they were all withdrawn between 1934 and 1952

20.
Firebox (steam engine)
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In a steam engine, the firebox is the area where the fuel is burned, producing heat to boil the water in the boiler. Most are somewhat box-shaped, hence the name, the hot gases generated in the firebox are pulled through a rack of tubes running through the firebox boiler. In the standard steam locomotive type boiler, the firebox is surrounded by water space on five sides. The bottom of the firebox is open to atmospheric pressure, if the engine burns solid fuel, like wood or coal, there is a grate covering most of the bottom of the firebox to hold the fire. An ashpan, mounted underneath the firebox and below the grates, catches and collects hot embers, ashes, in a coal-burning locomotive, the grates may be shaken to clean dead ash from the bottom of the fire. They are shaken either manually or by a powered grate shaker, wood-burning locomotives have fixed grates that cant be shaken. Wood ash is generally powder which will fall through the grates with no more required than the vibrations of the locomotive rolling down the track. The fire grates must be replaced due to the extreme heat they must endure. Combustion air enters through the bottom of the firebox and airflow is usually controlled by damper doors above the ash collection pocket of the ash pan, a locomotive that burns liquid fuel - usually Bunker C fuel oil or similar heavy oil - does not have grates. Instead, they have a metal gauge firing pan bolted tight against the bottom of the firebox. The firing pan is covered with firebrick and the firebox has a lining, usually up to the level of the firebox door. The oil burner is a nozzle containing a slot for the oil to flow out onto a steam jet which atomizes the oil into a fine mist which ignites in the firebox. The oil burner nozzle is mounted in the front of the firebox, protected by a hood of firebrick. Dampers control air flow to the oil fire, there is a large brick arch the front third to half of the firebox. It is supported on arch tubes, thermic syphons, or circulators, the brick arch directs heat, flames, and smoke back over the fire towards the rear of the firebox. Visible smoke contains unburned combustible carbon particles and combustible gasses, the purpose of this redirection is to cause more complete combustion of these particles and gasses which make the locomotive more efficient and causes less visible smoke to be emitted from the stack. Without the arch, flames and visible smoke would be sucked straight into the firetubes without having been fully burned, the brick arch and its supports require periodic replacement due to the extreme heat they endure. Firetubes are attached to one wall of the firebox and carry the hot gaseous products of combustion through the water, heating it

21.
Great Western Railway Power Classification
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The letter showed the power classification, and the coloured disc showed the weight restriction. This system continued after the GWR became the Western Region of British Railways, on 1 July 1905 the Great Western Railway introduced a system for denoting both the haulage capabilities and the weight restrictions which applied to their various classes of locomotive. Originally this was used only in books, but from mid 1919 began to be shown on the locomotives themselves. The weight restriction was shown in the form of a disc. The GWR was nationalised in 1948, becoming the Western Region of British Railways, in 1949, BR decided to adopt the London, Midland and Scottish Railway system of power classification for all locomotives. Certain ex-LMS and BR Standard steam locomotives allocated to the Western Region were given GWR style route classification discs, some of these had the BR power class shown on the disc as a figure, for example, the Class 5 4-6-0 bore the figure 5 on a red disc. The coloured disc was also applied to some diesel locomotives allocated to the Western Region,111 The Great Bear, Special was shown by a cross on its red route restriction disc. Locomotives loaned during World War II were given GWR power class letters, also during World War II, it was decided that some classes of two-cylinder engines would be permitted to haul loads heavier than those specified in the working books for their power classification. These engines were distinguished by a white letter X painted above the number plate, in between these were dotted red and dotted blue routes, where overweight engines were permitted subject to speed restrictions. In addition, there were the red routes, where any locomotive was permitted. Further routes were raised to this category after Nationalisation, Wolverhampton to Chester via Shrewsbury, for example, engines of LNER Class J25, which were Route Availability 3 on that line, were placed in GWR route restriction Yellow. Abc British Railway Locomotives, Combined volume Part One- Western Region, davies, F. K. le Fleming, H. M. Maskelyne, J. N. The Locomotives of the Great Western Railway, Part 5, Tender Engines - Classes J1 to J37. Le Fleming, H. M. White, D. E. ed, the Locomotives of the Great Western Railway. Le Fleming, H. M. White, D. E. ed, the Locomotives of the Great Western Railway. Volume Two, The 4-6-0 and 2-6-0 Classes, a Detailed History of British Railways Standard Steam Locomotives

22.
First World War
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World War I, also known as the First World War, the Great War, or the War to End All Wars, was a global war originating in Europe that lasted from 28 July 1914 to 11 November 1918. More than 70 million military personnel, including 60 million Europeans, were mobilised in one of the largest wars in history and it was one of the deadliest conflicts in history, and paved the way for major political changes, including revolutions in many of the nations involved. The war drew in all the worlds great powers, assembled in two opposing alliances, the Allies versus the Central Powers of Germany and Austria-Hungary. These alliances were reorganised and expanded as more nations entered the war, Italy, Japan, the trigger for the war was the assassination of Archduke Franz Ferdinand of Austria, heir to the throne of Austria-Hungary, by Yugoslav nationalist Gavrilo Princip in Sarajevo on 28 June 1914. This set off a crisis when Austria-Hungary delivered an ultimatum to the Kingdom of Serbia. Within weeks, the powers were at war and the conflict soon spread around the world. On 25 July Russia began mobilisation and on 28 July, the Austro-Hungarians declared war on Serbia, Germany presented an ultimatum to Russia to demobilise, and when this was refused, declared war on Russia on 1 August. Germany then invaded neutral Belgium and Luxembourg before moving towards France, after the German march on Paris was halted, what became known as the Western Front settled into a battle of attrition, with a trench line that changed little until 1917. On the Eastern Front, the Russian army was successful against the Austro-Hungarians, in November 1914, the Ottoman Empire joined the Central Powers, opening fronts in the Caucasus, Mesopotamia and the Sinai. In 1915, Italy joined the Allies and Bulgaria joined the Central Powers, Romania joined the Allies in 1916, after a stunning German offensive along the Western Front in the spring of 1918, the Allies rallied and drove back the Germans in a series of successful offensives. By the end of the war or soon after, the German Empire, Russian Empire, Austro-Hungarian Empire, national borders were redrawn, with several independent nations restored or created, and Germanys colonies were parceled out among the victors. During the Paris Peace Conference of 1919, the Big Four imposed their terms in a series of treaties, the League of Nations was formed with the aim of preventing any repetition of such a conflict. This effort failed, and economic depression, renewed nationalism, weakened successor states, and feelings of humiliation eventually contributed to World War II. From the time of its start until the approach of World War II, at the time, it was also sometimes called the war to end war or the war to end all wars due to its then-unparalleled scale and devastation. In Canada, Macleans magazine in October 1914 wrote, Some wars name themselves, during the interwar period, the war was most often called the World War and the Great War in English-speaking countries. Will become the first world war in the sense of the word. These began in 1815, with the Holy Alliance between Prussia, Russia, and Austria, when Germany was united in 1871, Prussia became part of the new German nation. Soon after, in October 1873, German Chancellor Otto von Bismarck negotiated the League of the Three Emperors between the monarchs of Austria-Hungary, Russia and Germany

23.
Great Western Railway Weight Classification
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The letter showed the power classification, and the coloured disc showed the weight restriction. This system continued after the GWR became the Western Region of British Railways, on 1 July 1905 the Great Western Railway introduced a system for denoting both the haulage capabilities and the weight restrictions which applied to their various classes of locomotive. Originally this was used only in books, but from mid 1919 began to be shown on the locomotives themselves. The weight restriction was shown in the form of a disc. The GWR was nationalised in 1948, becoming the Western Region of British Railways, in 1949, BR decided to adopt the London, Midland and Scottish Railway system of power classification for all locomotives. Certain ex-LMS and BR Standard steam locomotives allocated to the Western Region were given GWR style route classification discs, some of these had the BR power class shown on the disc as a figure, for example, the Class 5 4-6-0 bore the figure 5 on a red disc. The coloured disc was also applied to some diesel locomotives allocated to the Western Region,111 The Great Bear, Special was shown by a cross on its red route restriction disc. Locomotives loaned during World War II were given GWR power class letters, also during World War II, it was decided that some classes of two-cylinder engines would be permitted to haul loads heavier than those specified in the working books for their power classification. These engines were distinguished by a white letter X painted above the number plate, in between these were dotted red and dotted blue routes, where overweight engines were permitted subject to speed restrictions. In addition, there were the red routes, where any locomotive was permitted. Further routes were raised to this category after Nationalisation, Wolverhampton to Chester via Shrewsbury, for example, engines of LNER Class J25, which were Route Availability 3 on that line, were placed in GWR route restriction Yellow. Abc British Railway Locomotives, Combined volume Part One- Western Region, davies, F. K. le Fleming, H. M. Maskelyne, J. N. The Locomotives of the Great Western Railway, Part 5, Tender Engines - Classes J1 to J37. Le Fleming, H. M. White, D. E. ed, the Locomotives of the Great Western Railway. Le Fleming, H. M. White, D. E. ed, the Locomotives of the Great Western Railway. Volume Two, The 4-6-0 and 2-6-0 Classes, a Detailed History of British Railways Standard Steam Locomotives

24.
Aston Tirrold
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Aston Tirrold is a village and civil parish at the foot of the Berkshire Downs about 3 miles southeast of Didcot. It was part of Berkshire until the 1974 boundary changes transferred it to Oxfordshire, the 2011 Census recorded the parishs population as 373. Aston is a toponym derived from the Old English for east town. It evolved via Eston and Extona in the 11th century and Eston in the 13th century before becoming Aston before the beginning of the 14th century. Tirrold began as Torald, Thorold and Thurroll in the 15th and 16th centuries, a Nicholas son of Torold held the manor in 1166. There may have been a church on the site of the Church of England parish church of Saint Michael since the Saxon period, the doorway is clearly not in its original position, as it links the 19th century north aisle with the vestry. The church is a Grade II* listed building, the Norman south doorway is 11th century. The nave and chancel were also Norman, built in the 12th century, the priests doorway and lancet windows survive from this time. The south transept is also from the first half of the 13th century but was remodeled in the first half of the 14th century, the Decorated Gothic east window of the chancel is also 14th century. Page and Ditchfield thought that the tower was from the first half of the 13th century. However, it is Perpendicular Gothic which suggests it is no earlier than the middle of the 14th century, st Michaels used to have a rood loft. It was removed, presumably during the English Reformation, and the stairs are now blocked, the upper and lower doorways to the stairs are late Perpendicular Gothic. In 1863 the church was restored and the Gothic Revival north aisle was added, the aisle has three bays designed in a 14th-century style. The organ loft was added in 1910 but includes a 15th-century Perpendicular Gothic window that may have come from the wall of the nave when the north aisle was built. The tower has a ring of six bells, the third bell was cast in about 1599, probably at Salisbury in Wiltshire. Joseph Carter of Reading, Berkshire cast the bell in 1603. Henry I Knight of Reading cast the bell in 1617. Lester and Pack of the Whitechapel Bell Foundry cast the bell in about 1769

25.
Nigel Gresley
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Sir Herbert Nigel Gresley CBE was one of Britains most famous steam locomotive engineers, who rose to become Chief Mechanical Engineer of the London and North Eastern Railway. He was the designer of some of the most famous steam locomotives in Britain, including the LNER Class A1, Gresleys engines were considered elegant, both aesthetically and mechanically. This rapid rise in his career was maintained for, in 1904, he became Assistant Superintendent of the Carriage, a year later, he moved to the Great Northern Railway as Carriage and Wagon Superintendent. He succeeded Henry A. Ivatt as CME of the GNR on 1 October 1911, at the 1923 Grouping, he was appointed CME of the newly formed LNER. In 1936, Gresley was awarded an honorary DSc by Manchester University, during the 1930s, Sir Nigel Gresley lived at Salisbury Hall, near St. Albans in Hertfordshire. Gresley developed an interest in breeding birds and ducks in the moat, intriguingly. The Hall still exists today as a residence and is adjacent to the de Havilland Aircraft Heritage Centre. In 1936, Gresley designed the 1, 500V DC locomotives for the electrification of the Woodhead Line between Manchester and Sheffield. The Second World War forced the postponement of the project, which was completed in the early 1950s, Gresley died after a short illness on 5 April 1941 and was buried in St Peters Church, Netherseal, Derbyshire. He was succeeded as the LNER CME by Edward Thompson, Gresley was awarded the CBE in 1920 and was knighted in the 1936 Birthday Honours. A memorial plaque to Gresleys achievements was unveiled at Edinburgh Waverley railway station in 2001 and it was created by the Gresley Society and incorporates line drawings of his Flying Scotsman and Mallard locomotives. Sir Nigel Gresley Square was opened to the Public as part of the Queens Diamond Jubilee celebrations by the Mayor of Doncaster Mr. Peter Davies, LNER Class A44498 Sir Nigel Gresley is named after its designer. A statue of Gresley was unveiled at Kings Cross station in London on 5 April 2016, derived valve motion for 3-cylinder steam locomotives, Gresley Conjugated Valve Gear. The largest passenger locomotive in the UK, the P2 2-8-2. The largest steam locomotive in the UK, the U1 2-8-0+0-8-2 Garratt, the locomotive that won the war, the V2 2-6-2. The fastest steam locomotive in the world, the A4 Mallard 4-6-2,6701 Bo+Bo electric locomotive Hughes, Geoffrey. Sir Nigel Gresley, The Engineer and his Family, the Oakwood Library of Railway History

26.
Great Northern Railway (Great Britain)
–
The Great Northern Railway was a British railway company established by the Great Northern Railway Act of 1846. On 1 January 1923 the company lost its identity, as a constituent of the newly formed London, the main line became part of the East Coast Main Line. In the summer of 1835, the engineer, Joseph Gibbs projected a line which was to run from Whitechapel, via Dunmow, Cambridge, Sleaford and this was submitted to a committee in London to which the title Great Northern Railway Company was provisionally given. However, the scheme came to nothing, loop from Peterborough to Bawtry via Boston and Lincoln. The London and York bill finally received Royal assent on 26 June 1846 as The Great Northern Railway Act,1846, the Act granted powers to construct the main line and loop lines. The Great Northern began construction first on the Peterborough to Gainsborough section of the loop line, as the ease of construction over the flat fens promised an earlier return on investment. The first section of line was opened on 1 March 1848 and was the Louth to Grimsby section of the East Lincolnshire Railway, which although nominally independent, was leased to the GNR from the start. The first section of GNR proper to be opened was the 3 miles from Doncaster to Askern Junction, the GNR and MS&LR lines allowing through running from Lincoln to Doncaster via Retford opened on 4 September 1849. The immediate targets in the north were Leeds and York and this new line was opened in June 1850, at which time the agreement was formalised and in return the GNR agreed not to proceed with its own main line from Askern to York via Selby. During 1846 to 1849 George Turnbull was the resident engineer under William Cubitt for the London District of the Great Northern Railway, in December 1848 Turnbull was busy with the plans for Kings Cross station and passing the line under the Regents Canal. On 2 February 1849 the last capstone on Holloway Bridge was set in place, on 27 March the first brick for the South Mimms tunnel was laid by Edward Purser. The first brick of the East Barnet tunnel was laid on 23 April, there was much trouble with the cement in the Tottenham and South Mimms tunnels, Turnbull stopped the use of this cement — blue lias was substituted. Another of the engineers working under Cubitt was James Moore, who went on to design the first commercial railway in Australia for the Melbourne. On 7 August 1850, the line opened from a temporary station at Maiden Lane, London. The remaining section between Peterborough and Retford opened in 1852, as did the new London terminus at Kings Cross, Doncaster locomotive works opened in 1853, replacing temporary facilities at Boston. On 1 August 1854, the Leeds, Bradford and Halifax Junction Railway opened between Leeds and Bowling Junction near Bradford, because it had running powers over this line and a section of the LYR, the GNR obtained access to Bradford and Halifax. In 1857, the West Yorkshire Railway opened their line from Wakefield to Leeds via Ardsley. The GNR had running powers over this line and immediately began using it instead of the Midland line via Methley, also in 1857, the previously mentioned LB&HJR opened a direct line from Ardsley to Laisterdyke, near Bradford

27.
International Standard Serial Number
–
An International Standard Serial Number is an eight-digit serial number used to uniquely identify a serial publication. The ISSN is especially helpful in distinguishing between serials with the same title, ISSN are used in ordering, cataloging, interlibrary loans, and other practices in connection with serial literature. The ISSN system was first drafted as an International Organization for Standardization international standard in 1971, ISO subcommittee TC 46/SC9 is responsible for maintaining the standard. When a serial with the content is published in more than one media type. For example, many serials are published both in print and electronic media, the ISSN system refers to these types as print ISSN and electronic ISSN, respectively. The format of the ISSN is an eight digit code, divided by a hyphen into two four-digit numbers, as an integer number, it can be represented by the first seven digits. The last code digit, which may be 0-9 or an X, is a check digit. Formally, the form of the ISSN code can be expressed as follows, NNNN-NNNC where N is in the set, a digit character. The ISSN of the journal Hearing Research, for example, is 0378-5955, where the final 5 is the check digit, for calculations, an upper case X in the check digit position indicates a check digit of 10. To confirm the check digit, calculate the sum of all eight digits of the ISSN multiplied by its position in the number, the modulus 11 of the sum must be 0. There is an online ISSN checker that can validate an ISSN, ISSN codes are assigned by a network of ISSN National Centres, usually located at national libraries and coordinated by the ISSN International Centre based in Paris. The International Centre is an organization created in 1974 through an agreement between UNESCO and the French government. The International Centre maintains a database of all ISSNs assigned worldwide, at the end of 2016, the ISSN Register contained records for 1,943,572 items. ISSN and ISBN codes are similar in concept, where ISBNs are assigned to individual books, an ISBN might be assigned for particular issues of a serial, in addition to the ISSN code for the serial as a whole. An ISSN, unlike the ISBN code, is an identifier associated with a serial title. For this reason a new ISSN is assigned to a serial each time it undergoes a major title change, separate ISSNs are needed for serials in different media. Thus, the print and electronic versions of a serial need separate ISSNs. Also, a CD-ROM version and a web version of a serial require different ISSNs since two different media are involved, however, the same ISSN can be used for different file formats of the same online serial

28.
International Standard Book Number
–
The International Standard Book Number is a unique numeric commercial book identifier. An ISBN is assigned to each edition and variation of a book, for example, an e-book, a paperback and a hardcover edition of the same book would each have a different ISBN. The ISBN is 13 digits long if assigned on or after 1 January 2007, the method of assigning an ISBN is nation-based and varies from country to country, often depending on how large the publishing industry is within a country. The initial ISBN configuration of recognition was generated in 1967 based upon the 9-digit Standard Book Numbering created in 1966, the 10-digit ISBN format was developed by the International Organization for Standardization and was published in 1970 as international standard ISO2108. Occasionally, a book may appear without a printed ISBN if it is printed privately or the author does not follow the usual ISBN procedure, however, this can be rectified later. Another identifier, the International Standard Serial Number, identifies periodical publications such as magazines, the ISBN configuration of recognition was generated in 1967 in the United Kingdom by David Whitaker and in 1968 in the US by Emery Koltay. The 10-digit ISBN format was developed by the International Organization for Standardization and was published in 1970 as international standard ISO2108, the United Kingdom continued to use the 9-digit SBN code until 1974. The ISO on-line facility only refers back to 1978, an SBN may be converted to an ISBN by prefixing the digit 0. For example, the edition of Mr. J. G. Reeder Returns, published by Hodder in 1965, has SBN340013818 -340 indicating the publisher,01381 their serial number. This can be converted to ISBN 0-340-01381-8, the check digit does not need to be re-calculated, since 1 January 2007, ISBNs have contained 13 digits, a format that is compatible with Bookland European Article Number EAN-13s. An ISBN is assigned to each edition and variation of a book, for example, an ebook, a paperback, and a hardcover edition of the same book would each have a different ISBN. The ISBN is 13 digits long if assigned on or after 1 January 2007, a 13-digit ISBN can be separated into its parts, and when this is done it is customary to separate the parts with hyphens or spaces. Separating the parts of a 10-digit ISBN is also done with either hyphens or spaces, figuring out how to correctly separate a given ISBN number is complicated, because most of the parts do not use a fixed number of digits. ISBN issuance is country-specific, in that ISBNs are issued by the ISBN registration agency that is responsible for country or territory regardless of the publication language. Some ISBN registration agencies are based in national libraries or within ministries of culture, in other cases, the ISBN registration service is provided by organisations such as bibliographic data providers that are not government funded. In Canada, ISBNs are issued at no cost with the purpose of encouraging Canadian culture. In the United Kingdom, United States, and some countries, where the service is provided by non-government-funded organisations. Australia, ISBNs are issued by the library services agency Thorpe-Bowker

29.
Locomotive
–
A locomotive or engine is a rail transport vehicle that provides the motive power for a train. A locomotive has no payload capacity of its own, and its purpose is to move the train along the tracks. In contrast, some trains have self-propelled payload-carrying vehicles and these are not normally considered locomotives, and may be referred to as multiple units, motor coaches or railcars. The use of these vehicles is increasingly common for passenger trains. Traditionally, locomotives pulled trains from the front, however, push-pull operation has become common, where the train may have a locomotive at the front, at the rear, or at each end. Prior to locomotives, the force for railroads had been generated by various lower-technology methods such as human power, horse power. The first successful locomotives were built by Cornish inventor Richard Trevithick, in 1804 his unnamed steam locomotive hauled a train along the tramway of the Penydarren ironworks, near Merthyr Tydfil in Wales. Although the locomotive hauled a train of 10 long tons of iron and 70 passengers in five wagons over nine miles, the locomotive only ran three trips before it was abandoned. Trevithick built a series of locomotives after the Penydarren experiment, including one which ran at a colliery in Tyneside in northern England, the first commercially successful steam locomotive was Matthew Murrays rack locomotive, Salamanca, built for the narrow gauge Middleton Railway in 1812. This was followed in 1813 by the Puffing Billy built by Christopher Blackett and William Hedley for the Wylam Colliery Railway, Puffing Billy is now on display in the Science Museum in London, the oldest locomotive in existence. In 1814 George Stephenson, inspired by the locomotives of Trevithick. He built the Blücher, one of the first successful flanged-wheel adhesion locomotives, Stephenson played a pivotal role in the development and widespread adoption of steam locomotives. His designs improved on the work of the pioneers, in 1825 he built the Locomotion for the Stockton and Darlington Railway, north east England, which became the first public steam railway. In 1829 he built The Rocket which was entered in and won the Rainhill Trials and this success led to Stephenson establishing his company as the pre-eminent builder of steam locomotives used on railways in the United Kingdom, the United States and much of Europe. The first inter city passenger railway, Liverpool and Manchester Railway, opened in 1830, there are a few basic reasons to isolate locomotive train power, as compared to self-propelled vehicles. Maximum utilization of power cars Separate locomotives facilitate movement of costly motive power assets as needed, flexibility Large locomotives can substitute for small locomotives when more power is required, for example, where grades are steeper. As needed, a locomotive can be used for freight duties. Obsolescence cycles Separating motive power from payload-hauling cars enables replacement without affecting the other, to illustrate, locomotives might become obsolete when their associated cars did not, and vice versa

30.
Broad gauge
–
Broad-gauge railways use a track gauge greater than the 1,435 mm standard gauge. In Britain the Great Western Railway, designed by Isambard Kingdom Brunel, pioneered broad gauge in 1838 with a gauge of 7 ft 1⁄4 in, some harbours also used railways of this gauge for construction and maintenance. These included Portland Harbour and Holyhead Breakwater, which used a locomotive for working sidings, as it was not connected to the national network, this broad-gauge operation continued until the locomotive wore out in 1913. The gauge initially proposed by Brunel was 7 ft exactly but this was increased by 1⁄4 in to accommodate clearance problems identified during early testing. It became apparent that standardization on a gauge throughout a rail transport system was advantageous. Rolling stock did not need to match the gauge exactly, a difference of a few millimetres could be coped with, the value of interoperability was initially not obvious to the industry. The standardization movement was gradual, over time the value of a proprietary gauge diminished, being replaced by the idea of charging money for equipment used on other railway lines. Ireland, using the criteria, was allocated a different standard gauge. Broad-gauge lines in Britain were gradually converted to dual gauge or standard gauge from 1864, Ireland and some states in Australia and Brazil have a gauge of 5 ft 3 in, but Luas, the Dublin light rail system, is built to standard gauge. Russia and the other former Soviet Republics use a 1,520 mm gauge while Finland continues to use the 5 ft gauge inherited from Imperial Russia, in 1839 the Netherlands started its railway system with two broad-gauge railways. But the neighbouring countries Prussia and Belgium already used standard gauge, in 1855, NRS regauged its line and shortly afterwards connected to the Prussian railways. There are replicas of one broad-gauge 2-2-2 locomotive and three carriages in the Dutch Railway Museum in Utrecht and these replicas were built for the 100th anniversary of the Dutch Railways in 1938–39. Portugal and the Spanish Renfe system use a gauge of 1,668 mm called Ancho Ibérico in Spanish or Bitola Ibérica in Portuguese, in India, Pakistan and Bangladesh, a gauge of 5 ft 6 in is widespread. This is also used by the Bay Area Rapid Transit system of the San Francisco Bay Area. In Toronto, Canada the gauge for TTC subways and streetcars was chosen in 1861, years after the establishment of gauge in Britain. In 1861, the province was supplying subsidies only to broad gauge railways. The use of a non-standard gauge precludes interoperability of rolling stock on railway networks. On the 5 ft 3 in and 5 ft 6 in gauges, the extra width allowed bigger inside cylinders and greater power, in the event, the most powerful engines on standard gauge in North America and Scandinavia far exceeded the power of any broad-gauge locomotive

31.
Isambard Kingdom Brunel
–
Brunel built dockyards, the Great Western Railway, a series of steamships including the first propeller-driven transatlantic steamship, and numerous important bridges and tunnels. His designs revolutionised public transport and modern engineering, though Brunels projects were not always successful, they often contained innovative solutions to long-standing engineering problems. Brunel set the standard for a railway, using careful surveys to minimise grades and curves. This necessitated expensive construction techniques, new bridges, new viaducts, one controversial feature was the wide gauge, a broad gauge of 7 ft 1⁄4 in, instead of what was later to be known as standard gauge of 4 ft 8 1⁄2 in. Brunel astonished Britain by proposing to extend the Great Western Railway westward to North America by building steam-powered iron-hulled ships and he designed and built three ships that revolutionised naval engineering, the Great Western, the Great Britain, and the Great Eastern. In 2002, Brunel was placed second in a BBC public poll to determine the 100 Greatest Britons, in 2006, the bicentenary of his birth, a major programme of events celebrated his life and work under the name Brunel 200. Brunels name is an amalgamation of his parents names and he inherited the family name of his father, and his middle name is his mothers surname. Brunels first name, Isambard, comes from his fathers middle name, Isambard is a Norman name of Germanic origin, meaning iron-bright. A cognate name is the German surname Eisenbarth, which can still be found today among Bavarians and German-Americans and he had two older sisters, Sophia and Emma, and the whole family moved to London in 1808 for his fathers work. Brunel had a childhood, despite the familys constant money worries. His father taught him drawing and observational techniques from the age of four, during this time he also learned fluent French and the basic principles of engineering. He was encouraged to draw interesting buildings and identify any faults in their structure, when Brunel was eight he was sent to Dr Morrells boarding school in Hove, where he learned the classics. When Brunel was 15, his father Marc, who had accumulated debts of over £5,000, was sent to a debtors prison. After three months went by with no prospect of release, Marc let it be known that he was considering an offer from the Tsar of Russia. In August 1821, facing the prospect of losing a prominent engineer, Brunel subsequently studied under the prominent master clockmaker and horologist Abraham-Louis Breguet, who praised Brunels potential in letters to his father. In late 1822, having completed his apprenticeship, Brunel returned to England, Brunels father, Marc, was the chief engineer, and the project was funded by the Thames Tunnel Company. The composition of the riverbed at Rotherhithe was often more than waterlogged sediment. The latter incident, in 1828, killed the two most senior miners, and Brunel himself narrowly escaped death and he was seriously injured, and spent six months recuperating

32.
GWR Hurricane locomotive
–
Hurricane was the second of a pair of steam locomotives built for the Great Western Railway by R. & W. Hawthorn & Co. whose design was very different from other locomotives. In order to meet Isambard Kingdom Brunels strict specifications, a 2-2-2 frame carried the engine, GWR Thunderer locomotive - the other Hawthorn locomotive GWR Haigh Foundry locomotives - further geared locomotives Reed, P. J. T. The Locomotives of the Great Western Railway, Part 2, Broad Gauge, kenilworth, Railway Correspondence and Travel Society

Great Western Railway
–
The Great Western Railway was a British railway company that linked London with the south-west and west of England, the Midlands, and most of Wales. It was founded in 1833, received its enabling Act of Parliament on 31 August 1835, Goods wagons were painted red but this was later changed to mid-grey. Great Western trains included long-distance expr

1.
The interior of Brunel's train-shed at Temple Meads, the first Bristol terminus of the GWR, from an engraving by J. C. Bourne.

2.
Coat-of-arms of the Great Western Railway, incorporating the shields, crests and mottoes of the cities of London (left) and Bristol (right)

3.
The Sonning Cutting in 1846

4.
Route of the Great Western Railway on Cheffin's Map, 1850

Swindon Works
–
Swindon railway works were built by the Great Western Railway in 1841 in Swindon, Wiltshire, United Kingdom. In 1835 Parliament approved the construction of a railway between London and Bristol and its Chief Engineer was Isambard Kingdom Brunel. From 1836, Brunel had been buying locomotives from various makers for the new railway, in 1837, Brunel r

1.
GWR King Class locomotives under construction, 1928

2.
"Western" diesel-hydraulic locomotives nos D1052 and D1009 in ex-works condition outside the main works buildings.

3.
Preserved housing originally built for the railway workers, January 2006

4.
An early GWR Saint class, in the period when these were taper-boilered 4-4-2 Atlantics (1905–12), in the testing shop

Whyte notation
–
The notation counts the number of leading wheels, then the number of driving wheels, and finally the number of trailing wheels, groups of numbers being separated by dashes. Other classification schemes, like UIC classification and the French, Turkish and Swiss systems for steam locomotives, in the notation a locomotive with two leading axles in fro

1.
Whyte notation from a handbook for railroad industry workers published in 1906

Track gauge
–
In rail transport, track gauge is the spacing of the rails on a railway track and is measured between the inner faces of the load-bearing rails. All vehicles on a network must have running gear that is compatible with the track gauge, as the dominant parameter determining interoperability, it is still frequently used as a descriptor of a route or n

1.
Indian Narrow and Broad gauge tracks

2.
Track gauge

3.
Fish-belly cast-iron rails from the Cromford and High Peak Railway

4.
An early Stephenson locomotive

Standard gauge
–
The standard gauge is a widely used railway track gauge. Approximately 55% of the lines in the world are this gauge, all high-speed rail lines, except those in Russia, Uzbekistan, and Finland, are standard gauge. The distance between the edges of the rails is defined to be 1435 mm except in the United States. It is also called the UIC gauge or UIC

1.
Track gauge

Leading wheel
–
The leading wheel or leading axle or pilot wheel of a steam locomotive is an unpowered wheel or axle located in front of the driving wheels. The axle or axles of the wheels are normally located on a leading truck. Leading wheels are used to help the locomotive negotiate curves and to support the front portion of the boiler, importantly, the leading

1.
The leading wheels (boxed) on a 4-6-2 locomotive

Driving wheel
–
Driving Wheel, also called Drivin Wheel or Driving Wheel Blues, is blues song recorded by Roosevelt Sykes in 1936. It became a standard of the blues and has been recorded by artists, including Junior Parker and Al Green. Roosevelt Sykes Driving Wheel Blues is a solo twelve-bar blues, with Sykes providing piano accompaniment to his vocal, the song i

1.
"Driving Wheel Blues"

Trailing wheel
–
On a steam locomotive, a trailing wheel or trailing axle is generally an unpowered wheel or axle located behind the driving wheels. The axle of the wheels is usually located in a trailing truck. On some large locomotives, an engine was mounted on the trailing truck to provide extra tractive effort when starting a heavy train. Trailing wheels were u

Wheelbase
–
In both road and rail vehicles, the wheelbase is the distance between the centers of the front and rear wheels. For road vehicles with more than two axles, the wheelbase is defined as the distance between the axle and the centerpoint of the driving axle group. In the case of a truck, the wheelbase would be the distance between the steering axle and

1.
Wheelbase (measured between rotational centers of wheels)

Tonne
–
The SI symbol for the tonne is t, adopted at the same time as the unit itself in 1879. Its use is also official, for the metric ton, within the United States, having been adopted by the US National Institute of Standards and it is a symbol, not an abbreviation, and should not be followed by a period. Informal and non-approved symbols or abbreviatio

1.
Base units

Bogie
–
A bogie is a chassis or framework carrying wheels, attached to a vehicle, thus serving as a modular subassembly of wheels and axles. Bogies take various forms in various modes of transport, while bogie is the preferred spelling and first-listed variant in various dictionaries, bogey and bogy are also used. A bogie in the UK, or a truck, wheel truck

1.
A diamond bogie with axle boxes, known in American English as a "truck"

2.
Commonwealth bogie as used on BR Mark 1 and CIE Park Royals

3.
B4 bogie as used on BR Mark 2 and Irish Cravens

4.
Side view of a SEPTA K-Car bogie

Coal
–
Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams. The harder forms, such as coal, can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure. Coal is composed primarily of carbon, along with quantities of other el

1.
Anthracite coal

2.
Bituminous coal

3.
Coastal exposure of the Point Aconi Seam (Nova Scotia)

4.
Coal miner in Britain, 1942

Cylinder (locomotive)
–
The cylinders of a steam locomotive are the components that convert the power stored in the steam into motion. Cylinders may be arranged in different ways. On early locomotives, such as Puffing Billy, the cylinders were often set vertical, the next stage, for example Stephensons Rocket, was to drive the wheels directly from steeply inclined cylinde

1.
The 'motion' on the left-hand side of 60163 Tornado. The black casting to the left houses the cylinder, in which slides the piston; the piston rod is immediately above the wheel.

2.
The cylinders on a Shay locomotive.

Tractive force
–
In railway engineering, the term tractive effort is often used synonymously with tractive force to describe the pulling or pushing capability of a locomotive. The published tractive force value for any vehicle may be theoretical—that is, the term tractive effort is often qualified as starting tractive effort, continuous tractive effort and maximum

1.
Diagram of tractive effort versus speed for a hypothetical locomotive with power at rail of ~7000 kW

Great Western Main Line
–
The Great Western main line is a main line railway in Great Britain, that runs westwards from Londons Paddington station to Bristol Temple Meads. It was the route of the pre-1948 Great Western Railway which was merged into the Western Region of British Railways and is now a part of the national rail system managed by Network Rail. The line is curre

1.
Maidenhead Railway Bridge carrying the line over the River Thames.

London Paddington station
–
Paddington, also known as London Paddington, is a central London railway terminus and London Underground station complex, located on Praed Street in the Paddington area. The site has been the London terminus of the Great Western Railway, much of the main-line station dates from 1854 and was designed by Isambard Kingdom Brunel. It was first served b

1.
The main Praed Street entrance and the Victorian train shed

2.
Paddington Station in 1888

3.
Paddington Station in Victorian Times

4.
The four arches of the station roof, including Span 4 (far left) prior to restoration

Bristol Temple Meads railway station
–
Bristol Temple Meads is the oldest and largest railway station in Bristol, England. It is an important transport hub for transport in the city. In addition to the services there are bus services to many parts of the city and surrounding districts. Bristols other main station, Bristol Parkway, is on the northern outskirts of the conurbation. Temple

1.
Facade of the station.

2.
Engraving of interior of Brunel's train-shed from c1843, by John Cooke Bourne.

3.
Brunel's original station as it appears today.

4.
The Bristol and Exeter Railway headquarters

GWR 4073 Class
–
The 4073 Class or Castle class were 4-6-0 steam locomotives of the Great Western Railway design built between 1923 and 1950. They were designed by the railways Chief Mechanical Engineer, Charles Collett, the Star class were designed to take the top express trains on the GWR with 61 in service by 1914, but after World War 1 there was a need for an i

1.
5034 Corfe Castle fresh from Swindon Works, 1954.

2.
GWR 4079 Pendennis Castle at Chester General station before hauling the return Birkenhead Flyer to Birmingham, 4 March 1967

3.
Castle class locos 5051 and 5029 climb St Germans bank

GWR 4000 Class
–
The Great Western Railway 4000 or Star were a class of 4-cylinder 4-6-0 Ten Wheeler passenger steam locomotives designed by George Jackson Churchward for the Great Western Railway in 1906. The prototype was built as a 4-4-2 Atlantic and they proved to be a successful design which handled the heaviest long distance express trains and established the

1.
4003 Lode Star.

2.
Star class prototype No. 40 as built as a 4-4-2

3.
First series No. 4003 Lode Star, at Tyseley Locomotive Works

4.
No. 4025 - after the name Italian Monarch was removed in 1940

Firebox (steam engine)
–
In a steam engine, the firebox is the area where the fuel is burned, producing heat to boil the water in the boiler. Most are somewhat box-shaped, hence the name, the hot gases generated in the firebox are pulled through a rack of tubes running through the firebox boiler. In the standard steam locomotive type boiler, the firebox is surrounded by wa

1.
The firedoor into the firebox of a steam locomotive. The firebox is approximately 3,500 degrees F (~1900 ℃)

2.
Cutaway of locomotive firebox and boiler with radial stays

3.
The flat sides and square corners show the shape of the Belpaire firebox. This offers a greater heating surface, increasing the efficiency of the engine

4.
Locomotive with a normal firebox. The round top of the firebox makes attaching the boiler easier

Great Western Railway Power Classification
–
The letter showed the power classification, and the coloured disc showed the weight restriction. This system continued after the GWR became the Western Region of British Railways, on 1 July 1905 the Great Western Railway introduced a system for denoting both the haulage capabilities and the weight restrictions which applied to their various classes

1.
A preserved GWR 2884 Class steam locomotive, showing the power classification as a black letter "E" on a blue weight classification disc, painted above the numberplate. Between the disc and numberplate may be seen a white letter "X", which affects how the power class is interpreted

3.
Two Western Region Diesel-hydraulic locomotives; D7072 (left) is a class 35 showing a red route restriction disc; D6343 (right) is a class 22 and has a yellow disc. Both discs are on the cabsides, below the numbers.

4.
An ex-GWR 6800 (Grange) class steam locomotive, showing a white "X" below the red route restriction disc, indicating that the normal loads for its power class (D) could be exceeded

First World War
–
World War I, also known as the First World War, the Great War, or the War to End All Wars, was a global war originating in Europe that lasted from 28 July 1914 to 11 November 1918. More than 70 million military personnel, including 60 million Europeans, were mobilised in one of the largest wars in history and it was one of the deadliest conflicts i

1.
Clockwise from the top: The aftermath of shelling during the Battle of the Somme, Mark V tanks cross the Hindenburg Line, HMS Irresistible sinks after hitting a mine in the Dardanelles, a British Vickers machine gun crew wears gas masks during the Battle of the Somme, Albatros D.III fighters of Jagdstaffel 11

2.
Sarajevo citizens reading a poster with the proclamation of the Austrian annexation in 1908.

3.
This picture is usually associated with the arrest of Gavrilo Princip, although some believe it depicts Ferdinand Behr, a bystander.

4.
Serbian Army Blériot XI "Oluj", 1915.

Great Western Railway Weight Classification
–
The letter showed the power classification, and the coloured disc showed the weight restriction. This system continued after the GWR became the Western Region of British Railways, on 1 July 1905 the Great Western Railway introduced a system for denoting both the haulage capabilities and the weight restrictions which applied to their various classes

1.
A preserved GWR 2884 Class steam locomotive, showing the power classification as a black letter "E" on a blue weight classification disc, painted above the numberplate. Between the disc and numberplate may be seen a white letter "X", which affects how the power class is interpreted

3.
Two Western Region Diesel-hydraulic locomotives; D7072 (left) is a class 35 showing a red route restriction disc; D6343 (right) is a class 22 and has a yellow disc. Both discs are on the cabsides, below the numbers.

4.
An ex-GWR 6800 (Grange) class steam locomotive, showing a white "X" below the red route restriction disc, indicating that the normal loads for its power class (D) could be exceeded

Aston Tirrold
–
Aston Tirrold is a village and civil parish at the foot of the Berkshire Downs about 3 miles southeast of Didcot. It was part of Berkshire until the 1974 boundary changes transferred it to Oxfordshire, the 2011 Census recorded the parishs population as 373. Aston is a toponym derived from the Old English for east town. It evolved via Eston and Exto

1.
St Michael and All Angels parish church

2.
Aston Tirrold's 17th-century manor house

3.
Aston Tirrold United Reformed Church

Nigel Gresley
–
Sir Herbert Nigel Gresley CBE was one of Britains most famous steam locomotive engineers, who rose to become Chief Mechanical Engineer of the London and North Eastern Railway. He was the designer of some of the most famous steam locomotives in Britain, including the LNER Class A1, Gresleys engines were considered elegant, both aesthetically and mec

1.
Herbert Nigel Gresley

2.
No. 4472 Flying Scotsman

3.
Salisbury Hall, Gresley's home during the 1930s

4.
Memorial plaque to Gresley's achievements displayed in the main hall of Edinburgh's Waverley railway station

Great Northern Railway (Great Britain)
–
The Great Northern Railway was a British railway company established by the Great Northern Railway Act of 1846. On 1 January 1923 the company lost its identity, as a constituent of the newly formed London, the main line became part of the East Coast Main Line. In the summer of 1835, the engineer, Joseph Gibbs projected a line which was to run from

1.
Great Northern Railway Stirling "Single" 4-2-2 express locomotive at Peterborough North railway station. At their introduction in 1876, these were the fastest steam locomotives in the world.

2.
The Bennerley Viaduct on the Awsworth Junction to Derby Branch in 2006

3.
The former GNR works at Boston, Lincolnshire

4.
GNR designed stock built under the LNER in 1924

International Standard Serial Number
–
An International Standard Serial Number is an eight-digit serial number used to uniquely identify a serial publication. The ISSN is especially helpful in distinguishing between serials with the same title, ISSN are used in ordering, cataloging, interlibrary loans, and other practices in connection with serial literature. The ISSN system was first d

1.
ISSN encoded in an EAN-13 barcode with sequence variant 0 and issue number 5

International Standard Book Number
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The International Standard Book Number is a unique numeric commercial book identifier. An ISBN is assigned to each edition and variation of a book, for example, an e-book, a paperback and a hardcover edition of the same book would each have a different ISBN. The ISBN is 13 digits long if assigned on or after 1 January 2007, the method of assigning

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A 13-digit ISBN, 978-3-16-148410-0, as represented by an EAN-13 bar code

Locomotive
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A locomotive or engine is a rail transport vehicle that provides the motive power for a train. A locomotive has no payload capacity of its own, and its purpose is to move the train along the tracks. In contrast, some trains have self-propelled payload-carrying vehicles and these are not normally considered locomotives, and may be referred to as mul

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Three body styles of diesel locomotive: cab unit, hood unit and box cab. These locomotives are operated by Pacific National in Australia.

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R class steam locomotive number R707 as operated by the Victorian Railways of Australia.

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A Green Cargo RC 4 class electric locomotive repainted in its original livery for the Swedish 150-year railway anniversary in 2006.

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The first passenger railway, the Liverpool and Manchester Railway, in England.

Broad gauge
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Broad-gauge railways use a track gauge greater than the 1,435 mm standard gauge. In Britain the Great Western Railway, designed by Isambard Kingdom Brunel, pioneered broad gauge in 1838 with a gauge of 7 ft 1⁄4 in, some harbours also used railways of this gauge for construction and maintenance. These included Portland Harbour and Holyhead Breakwate

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Great Western Railway broad-gauge steam locomotives awaiting scrapping in 1892 after the conversion of the tracks to standard gauge.

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Track gauge

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Irish broad gauge tracks

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Broad gauge at MAS

Isambard Kingdom Brunel
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Brunel built dockyards, the Great Western Railway, a series of steamships including the first propeller-driven transatlantic steamship, and numerous important bridges and tunnels. His designs revolutionised public transport and modern engineering, though Brunels projects were not always successful, they often contained innovative solutions to long-

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Isambard Kingdom Brunel by the launching chains of the SS Great Eastern by Robert Howlett, 1857 (detail)

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The Maidenhead Railway Bridge, at the time the largest span for a brick arch bridge.

GWR Hurricane locomotive
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Hurricane was the second of a pair of steam locomotives built for the Great Western Railway by R. & W. Hawthorn & Co. whose design was very different from other locomotives. In order to meet Isambard Kingdom Brunels strict specifications, a 2-2-2 frame carried the engine, GWR Thunderer locomotive - the other Hawthorn locomotive GWR Haigh Foundry lo

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